Train stop and cab signal system



Sept. 27, 1932. A. E. HUDD TRAINSTOP AND CAB SIGNAL SYSTEM Filed Augfl,1928 3 Sheets-Sheet 3 Patented Sept. 27, 1932 UNITED STATES PATENTOFFECE ALFRED E. I-IUDD, 0F EVANSTON, ILLINOIS, ASSIGNOR, BY MESNEASSIGNMENTS, TO

ASSOCIATED ELECTRIC LABORATORIES,

TION OF DELAWARE INC., OF CHICAGO, ILLINOIS, A CORPORA- TRAIN STOP ANDCAB SIGNAL SYSTEM Application filed .August 1, 1928. Serial No. 296,652.

The present invention relates in general to train stop systems, but isparticularly concerned with the provision of a trainl stop sys tem ofthe intermittent inductive type and wherein cab signals are provided forindicatl ing the traffic conditions ahead.

`unit on the locomotive and only two trackway elements for each block ofthe trackway; to provide a novel receiver relay having more than twoarmatures and having a different magnetic circuit for each armature; toprovide a track way electromagnet capable of producing, alternatively,either of two magnetic fields at right angles to each other; and infact, to provide an extremely simple train stop system as hereinafterclaimed.

In the accompanying drawings, Fig. 1 diagrammatically discloses thelocomotive equipment of the train stop system; Figs. 2, 3, and 4diagrammatically show permanent and eloctromagnet trackwaj,7 elements,respectively, with diagrammatic sketches of the receiver relay, shown inthe lower portion of Fig. 1, superimposed thereon to illustrate theinfluence the trackway elements have upon the receiver Linder varioustraffic conditions, while Figs. 5 and 5A illustrate sections of trackwaywith associated circuits and apparatus for controlling the locomotiveequipment of Fig. 1.

The valve structure diagrammatically disclosed in the upper part of Fig.1 is a somewhat simplified modification of that shown in the cri-pendingKelly application, Serial No. 292,996, led July 16, 1928. This valve,like the one in the former application, is designed for insert-ion inthe brake line in substitution for Jr-he double heading cock, a doubleheading cock being part of the present valve structure. The purpose ofthis valve is to initiate an automatic service application of thebrakes; to prevent the release of an automatic brake application untila. predetermined time interval has elapsed, and to permit an emergencyapplication of the brakes at any time.

This valve has a main body 6, having an opening 7 for connection withthe usually provided brake applicator and an opening 3 for connectionwith the brake pipe line. Inside the valve body, a number of ports10-14, inclusive, are provided all of which ext-end from a milledsurface, forming a slide valve seat, 15. The port 10 connects with theopening 8 and has a branch 10 connecting with a second portion of thevalve body which will subsequently be described. The port 11 extendsdownward a short distance from the seat 15 and then connects withatmosphere. rectly downward and connects with atmosphere. The port 13extends downward parallel to the port 12, but is connected with a timingreservoir 50. The port 14 extends downward a short distance and thenextends horizontally into connection with a port 49.

The right portion of the valve body has a slide valve seat 36 providedwith a large ex* haust port 37 and in which seat the other end of thepreviously mentioned port 10 terminates.

The left portion of the valve structure is in the form of a cylinder, inwhich is mounted an automatic brake applying piston 19, having connectedto the right thereof, a slide valve member 20, which lies against thevalve seat 15 of the valve body. Connected with the left part of thepiston 19 is a cuplike member containing a compression spring 21. Thecup-like member on the piston 19 telescopes into a second cup-likemember 70 forming an air chamber 71 within these cup-like members and asecondary air chamber 72 surrounding these cup-like members. Two ori-The port 12 extends di` lices, 22 and 23, connect these chambers, whileo5 adapted to be normally maintained closed by an associatedelectropneumatic valve EPV when energized. A cut-out element 28 is,however, provided which may be turned up to mechanically close the port49. This cutout in practice is ordinarily provided with a seal, whichmust be broken before the same can be turned up to cut out the controlby the electropneumatic valve EPV.

Referring now to the right portion of the valve member, a dividingmember 9 serves as a bearing for a shaft 31, carrying the valve member2O and as a stop for an emergency piston return spring 33. Immediatelyto the right of the spring 33 is an emergency brake applicator piston32. This piston operates the slide valve member 34 over a slide valveseat 36.

Midway between the opposite ends of port 10, and at right angles theretois a double heading cock having a handle 43.

With the electropneumatic valve energized, which is its normalcondition, the air supply for holding the brakes released passes throughthe usual brake applicator valve (not shown) into opening 7 of the brakevalve structure, through the passage 7 of the slide valve member,through port 1() and the opening of the double heading cock and thenceinto the opening 8 and into the brake pipe line. Owing to the orifice 24in piston 19 and because of the orifices 22 and 23, brake pipe pressureis also built up in chambers 71 and 72. Also because of the orifices inelement 9 and piston 32, brake pipe pressure is built up on both sidesof the piston 32. The springs 21 and 33 are therefore normally effectiveto hold the pistons 19 and 32 to the right in the position in which theyare shown. If the electropneumatic valve EPV is de-energized, airexhausts through the outlet port 49 and through the whistle 5 at agreater rate than brake pipe air is permitted to enter chamber 72through the restricted orifices 24,

' 23, and 22. Consequently, after the pressure in chamber 7 2 falls to apoint where the pressure upon the right hand side of the serviceapplication piston 19 is suiiicient to overcome the spring 21 in chamber72 (approximately siX seconds, as designed) the service brakeapplication piston 19 will begin to move and will lirst close orifice23. Vhen the orifice 23 closes, the air supply to chamber 72 is greatlyreduced and the piston 19 with the slide valve member 20 will quicklymove to the extreme left.

The piston carries with it the slide valve 20, which, in its operatedposition, closes the air path formerly existing between openings 7 and 8and connects the latter opening Ato atmosphere by way of the port 10,passage 90, and exhaust port 11, to produce an automatic brakeapplication. The slide valve member also disconnects the timingreservo-ir from connection with atmosphere by way of ports 13 and 12 andinstead connects this reservoir with port 14 for a. purpose which Willsubsequently be madeclear.

To restore the piston 19 and slide valve member 20 to their initialpo-sition, the elecof this piston. The capacity of chambers 71 and 72 isvery limited and in order to prevent practically immediate automaticrelease of the brakes following the energization of the valve EPV thetiming reservoir was brought into communication with the chambers 72 and71. Because of the restricted orifice 22 and the capacity of reservoir50 an appreciable time elapses after reenergization of theelectropneumatic valve before the piston 19 and its valve member arereturned.

The receiver relay shown in the lower half of F ig. lis of the samegeneral character as thatshown in the co-pending Hudd application,Serial No. 281,656, filed May 31, 1928.

The present relay, however, has somewhat different magnetic circuits andhas three armatures instead of two. |The relay is built into anon-magnetic casing 51, which is suspended from a vehicle in inductiverelation with the track magnets shown in Figs. 2 to i;

5A, inclusive, and which will be described later. The relay consists ofthree inductor planes 52, 53, and 54, having pole pieces 7 7- 83, forattracting three armatures 55, 56, and

57. The free ends of armature are of north 'f'" 54 are made of soft ironand therefore are normally inert, but since the armatures are polarizedby the permanent magnets 58 and 59 these armatures will remainmagnetically biased to either associated inductor plane pole piece towhich they have been moved. Associated with the pole piece 8O is awinding 60 which is adapted to be energized when a key 6l, in the cab ofthe vehicle is actuated and when energized is effective to overcome theopposing bias produced by magnets 58 and 59 and moves the armature 56int-o engagement with the pole piece 80.

Referring now to Figs. 2, 3, and 4, the trackway magnets and theirinfluence on the receiver relay of Fig. 1 will next be described.

A permanent magnet trackway unit simply consists of a number ofpermanent bar magnets arranged to function as one large permanentmagnet, with the polarity as indicated on the drawings. This magnet .isvery powerful compared to -those in the ireceiver and consequently, ifthe receiver R vof Fig. i1 is `passed over the permanent magnet unit thebiasing effect produced by magnets.58 and 59 will be overcome andarmatures 55, 56, and 5.7 will be rotated in a clockwise direction intothe position in which they are shownin F ig.2, for the reason that whenthe receiver* unit passes within inductive relation of the fieldproduced by the tracl way magnet 95, the pole-piece of the in- `ductorplane 52 becomes of strong north polarity, while the pole-piece of theinductcr plane 58 becomes of south polarity. Since the armatures 55 and57 are polarized north, due to the presence of magnets 58 and 59, arepelling action will occur between these armatures and their associatedpole pieces 77 and 8l while an attractive force will be set up for thesearmatures by pole pieces 78 'and 82. The armature 56 is also rotatedinto association with the pole p'ece 79 because this armature is ofsouth polarity. The pole piece 80 assists the pole piece 79 by therepelling action it has on the armature 56.

The electromagnet trackway elements shown in Figs. 3 and i are alike andconsist of rectangular units having the same general outline as thepermanent magnet 95. These units have four windings 9699, inclusive.lflfhen the windings 98 and 99 are energized, a magnetic field of thesame strength as that of thc permanent magnet is set up and is in theopposite direction to that set up bythe permanent magnet 95, asindicated in Fig. 8. It will be obvious, therefore, that when thereceiver' R passes over this trackwa-y element, with the windings 98 and99 energized, armatures 55, 56, and 57 will be rotated in acounter-clockwise direction into the position in which they are shown inFig. 1 and as diagrammatically shown in Fig. 8.

lf, alternatively, windings 96 and 97 are energized when the receiver Rpasses over theV .electromagnet tracliway element, as illustrated inFig. l, a magnetic lield similar to, but at right angles to that setupby windings 98 and 99 is set up and consequently, the polepieee of theinductor plane 54 becomes of south polarity, while the pole-piece of theinductor planes 52 and 58 become of north polarity. Since the polarityinduced in the inductor planes 52 and 58 is the same, theefl'ectproduced by them is substantially neutral and therefore theassociated armatures 55 and 56 remain in the position to which they weremoved by passing over a permanent magnet trackway element. The armature57, however, is rotated in a counterclockwise direction due to theattractive infiuence set up inthe pole piece 83 of the inductor plane5-1. It should be noted that as the receiver relay l passes out of theinductive field ofthe electromagnet traclway elements, the-inductorplanes 52and 58 will pass through the field of the S poles of :thetrackway magnets which may induce weak magnetism of south polarityin-,tliepole-pieces of these inductor planes, but .without effect sincewhen they are of like polarity they will not tend to operate theirarmatures fat this time.

Referring nowto Figs. 5 and 5A, the track circuits and arrangementsofthe trackway magnets will be described. In Fig. 5 aportion of block A,a block B, and a porion of a block C are shown; while in Fig. 515i acontinuation ofthe block C, a blockl), and a portion of a block E areshown. These blocks are divided by track insulation 100. ,Y

The presence of vehicles in blocks A and block D is indicated. vAt theexit of each block, it will be noted, a permanent Ymagnet trackwayelement `.is placed .alongside ,the track. In advanceof each of thesepermanent, magnet trackway elements is placedan electromagnetictraclrway element. Each of these magnets is so spaced that slightly more'than six seconds will be consumed by a :train traveling at any speedabove a very low speed in traversing the distance between them. A.-t theentrance of each bock, a three position polarized relay is connectedacross the trackway rails for controlling'the current .supply to thetraclrway element, located at the exit end of the adjacent block and toalso supply current to a similar polarized traclway relay at theentrance end of the adjacent block. In the track circuits illustrated itis assumed that the block E and the next block in advance thereof areboth unoccupied. Under these circumstances, as will readily appearhereinafter, the current supplied to the rails of block E and thepolarizedtrack relay 105 will be in such a direction as to cause thearmatures 106 and 107 of this relay to be rotated into engagement withtheir left contacts. With the armatures 106 and 107 inthis position anoperating circuit for the polarized relay 104i, at the entrance end ofthe block D, may be traced from the negative terminal of battery 121,through the left contact and armature 106 of the relay 105, the armature107 and its left contact, through the windings 98 and 99 of' theelectromagnetic tracltway elements, t-he rail 108, the winding of thepolarized relay 104, to rail 109, conductor 110, and to the positiveterminal of the battery 121. The current flow to the relay 104 is in theappropriate direction to cause it to move its armatures 126 and 127 intoengagement with their left contacts, so that current supplied over theblock C to the polarized relay 108 will be in the appropriate directionto cause it to move its armatures 186 and 187 into engagement with theirleft contacts. However, in the present illustration, owing to thepresence of a vehicle 181 in block D, the polarized relay 104 receivesno current and consequently its arma- .tures 126 and 127 droptotheirneutralormid 2 position. lVith the armatures 126 and 127 in thisposition,a circuit for the polarized relay 103 is completed whichextends from the positive terminal ol' the trackway battery 140, throughthe mid Contact and armature 126, armature 127 and its mid contact, theconductor 112, the resistance 111, the lower rail of block C, throughthe winding of relay 103, the upper rail of block C, and the conductor150 to the negative terminal of the battery 140. The current flow to thepolarized relay 103, it will be noted, is in the opposite direction tothat supplied to the relay 104 and therefore the polarized relay 103rotates its armatures 136 and 137 intol engagement with their rightcontacts. lilith the armatures 136 and 137 in this position, current foroperating the polarized relay 102 at the entrance of block D is suppliedfrom the negative terminal of battery 131, through the right contact andarmature 136 et the polarized relay 103, armature 137 and its rightcontact, through the windings 97 and 96 of the associated trackwayelectromagnet, the lower rail of block B, the winding of the polarizedrelay 102, the upper rail of block B, and the conductor 160 to thepositive terminal of battery 131. The current iow to the polarized relay102 is therefore in the same directionas that supplied to relays 104;and 105 and consequently the armatures 1416 and 1117 of the relay 102will be rotated into engagement with their left contacts, therebycompleting circuits for feeding battery to the track relay of the blockA in the same direction as it is being fed to the track relay 102.

I will now consic er the circuits and apparatus under control of thearmatures 55, 56, and 57 of the receiver. These armatures as shown inFig. 1 are in the positions they assume while the vehicle is passingthrough a block which was entered under clear trafiic conditions. Underthese circumstances, a circuit for the green lamp 62 extends from thenegative terminal of the battery 3%-, over conductor71, the armature 57and its ccntact member 57', contact (5, through the conductor 83, thearmature 55 and its Contact memher 55', the contact 73, conductor 65,the lamp 62, conductor 69, conductor 67, contact 74,

contact member 56' and the asscciatet armature 56, conductor 86 andthrough the contact and acknowledging key 61 to the positive terminal ofthe battery 84. The green lamp 62 is therefore glowing and serves toindicate to the engineman that the train is traveling under cleartra'liic conditions. A branch of the traced circuit extends over theconductor to and through thewinding of an electro-pneumatic valve EPVwhich is built into and forms a part of the brake valve structure. Thisvalve when energized, as previously explained, prevents the escape ofair from the chambers 71 and 72.

In order to explain the operation of the system as a whole, it will beassumed that the equipment of Fig. 1 is on the vehicle 101 of block A, Fig. 5 and that the vehicle is traveling in the direction indicated bythe arrow. y

As the receiver R passes over and within the inliuence of the permanentmagnettrackway element 95 its armatures 55, 56, and 57 are rotated intothe position in which they are shown in F ig. 2. Armature 55, at itscontact member 55', breaks a point in the traced circuit through contact73 tor the green lamp 62, thereby extinguishing the green lamp and atits contact 72 prepares a point in a circuit :tor the yellow lamp 63; atits armature 56 the traced circuit through contact member 56' andcontact 73 through which ground was formerly supplied to the green lampand to the electropneumaticI valve EPV is broken and consequently, theelectropneumatic valve E-PV drops its stem, thereby permitting air toexhaust from the chamber 72 through the port 49 and the whistle 5, whichaudibly warns the engineman to be on tie alert for a possible change ofsignal indication.; at armature 57 and its associated Contact member 57and contact 75, a third point in the traced circuit for the green lamp62 is interrupted, and at the associated contact 76 a point in a circuitfor the red lamp 64 is prepared.

Since the associated electromagnet trackway element of block A has itswindings 93 and 99 energized the polarity of this electromagnet isopposite to that of the permanent magnet 95 and consequently, as thereceiver passes over this electromagnet trackway element the armatures55, 56, and 57 are rotated back into the position in which they areshown in Figs. l and 3. The formerly traced circuits for lighting thegreen lamp 62 and `for energizing the electropneumatic valve EPV aretherefore immediately reestablished and the actuation of the Whistle 5ceases. These signal changes serve to indicate to the engineman thatthey have entered a block under favorable trafic conditions, andtherefore no action on the part ot the engineman is required. lVhen thevehicle 101 reaches the exit portion of block B, the receiver R passesover the permanent magnet trackway element 95', which causes thearmatures of the relay R to be operated to bring about the same circuitchanges as when the receiver passed over the trackway magnet 95. Since,however, the block D is occupied the trackway circuits at the entranceto block C are such that the caution windings 96 and 97 of theelectromagnet trackway element, positioned a short distance in advanceof the permanent magnet trackway element 95', are energized.Consequently, the magnetic field set up by this trackway electromagnetis at right angles to that set up by the permanent magnet trackwayelement 95. When the receiver R passes over this trackway electromagnetonly the armaturev 57 isrestored, as illustrated in Fig. 4. Since the:circuit for the green lamp 62 remains interrupted at contact 73 andContact member 55, and also at contact member 56 and Contact 74, thegreen lamp remains extinguished. Also, since the circuit for theelectropneumatic valve EV must also pass through contact member 56 andVcontact 74, the electropneumatic valve remains deenergized and thewhistle 5 continues to sound and serves to audibly warn the engineman ofadverse traffic conditions ahead. Ordinarily, the engineman will heedthe warning given by the whistle 5 and will proceedI to forestall anautomatic brake application by operating the acknowledging key 61momentarily. When this key is operated a circuit is completed for thearmature restoring winding 60, via conductors 85 and 71, and thearmature56' is thereby restored to its initial position in which it is shown inFig. 1. The formerly traced circuit for the electropneumatic valve EPVis therefore re-estabiished through contact 74 and contact member 56as-soon as the acknowledging` key 61 is returned to its normal position.This' results in the port 49 being again closed and in the whistleceasing operation. The armature 57 in operating, at its contact member57 and contact 75 closed a point in the circuit of the yellow lamp 68which is completed following the acknowledging action from the negativeterminal of the battery 84, through conductor 71', armature 57 and itscontact member 57, the contact 75, conductor 88, armature 55, itscontact member contact 72, conductor 66, the yellow lamp 63, conductor69, conductor 67, contact 74, contact member 56', conductor 86 andthrough the normal contacts of the acknowledging key 61 to the positiveterminal of the battery 84. The yellow lamp 63 is therefore lighted asthe vehicle 101 progresses through block C and until the next signalchange occurs as the vehicle passes over the permanent trackway magnet952.

When the receiver R passes over the trackway magnet 952 the armatures 56and 57 are again rotated into the position in which they are shown inFig. 2 and consequently, the effect of having passed over theelectromagnet trackwayV element at the exit of block C is entirely wipedout. Since the block D is occupied by a vehicle 181, causing thearmatures 126 and 127 of the polarized relay 104 to assume their neutralor mid position, the circuits through all windings of the electromagnettrack-way element immediately in ad- Vance of the permanent magnettrackway element 952 are open. rThe circuit conditions which were set upby the receiver R in passing over the trackway magnet 952 thereforeremains and since the whistle 5 continues to sound the enginemen areaudibly informed that acknowledgment is again necessary.

Responsive to the acknowledging action, as

in the case when acknowledgement was made at the exit of block C,armature 56 is rotated in a counterclockwise direction, while thearmatures 55 and 57 remain in attracted relations with respect to thepole pieces 78 and 82, respectively. The formerly traced circuit for theelectropneumatic-valve EPV is therefore again established and thewhistle 5 silenced. A circuit is also completed for. the red lampA 64..rlhis circuit extends from the neoative pole of the battery 84, throughconductor 71, the contact member 57', contact 76, conductor 68, red lamp64, the conductor 67, contact 74, contact member 56', and over theconductor 86 and the acknowledging key 61 to the positive terminal ofthebattery 84. The lighting of the red lamp serves towarn the enginementhat they are entering a block which is already occupied and that theymust proceed with extreme caution.

It willnow be assumed that the enginemen fail: to acknowledge within thesix seconds of time interval allowed after passing the trackway magnet952. Under these circumstances, at the end of the six-second interval,sufficient air has been exhausted from the chamber 72 out through thewhistle 5 to permit the air pressure on the right sidevof the piston 1.9to become effective to move it and the valve member 2O to the left. Themovement of the valve member closes the normally open passage extendingbetween openings 7 and 8 via port 7', port 10, and the double headingcock, thereby preventing the brake pipe from beingv recharged while theslide valve member 20 is in its operated position. The movement of theslide valve member 20 also connects the port 10 to the service exhaustport 11 via bypass 90, thereby causing a brake pipe pressure reductionsuiiicient to cause a service brake application.

To release the brakes, after an automatic application, the enginemanmust first operate the acknowledging key 61 which, in a manner'alreadydescribed, is effective to energize the electropneumatic valve EPV andto complete the circuit for the yellow or red lamp, depending on thecondition of the receiver R. The energization of the electropneumaticvalve EPV, as previously explained, stops the actuation of the whistle 5and the exhaust of air from chamber 72. The air pressure in chambers 71and 72 therefore again arises at a rate determined by the port 22 andthe capacity of the reservoir 50. As soon as the pressure rises to apoint where it approxi'- mates that on the right side of the piston 19,the spring 21 will return the piston 19 and the valve member 2O to theirnormal positions, in which. they are shown, thus closing the passage 14and again opening the reservoir 50 to atmosphere through the by-pass invalve member 2O and the exhaust port 12. The slide valve member 2O inreturning to its normal position; also again blankets the plication, theengineman desires to amplify the application he c( n do so by moving thehandle of the brake applicator valve to the emergency position. Thiscauses an instantaneous exhaust of air to occur through the v, emergencyport of the brake applicator valve and results in a very'quick reductionin pressure being made in the air pressure on the left side of theemergency application piston 32. This permits the air on the right sideof the piston 32 to rapidly expand and move the emergency applicationpiston 32' to the left. As soon as this piston has moved a slightdistance, its continued movement is assisted by air supplied to theright of the piston from the brake pipe via the port 10 and the port 91.The movement ofthe piston 32 to the extreme left connects the port 10',via bypass 73 to the large emergency exhaust port 37. This quickreduction in the brake line results in an emergency application of thebrakes.

l It has been proposed that installations of cab signalling be madeWithout the provision of any train stop equipment. The present system isideal for an installation of this kind. In an installation of this kind,the electropneumatic valve EPV and Whistle 5 or their equivalent Will beconnected directly with the main reservoir; the visual and audiblesignal control equipment Will function in the same manner as when usedin conjunction With the brake applicator valve; and the enginemen willbe required to acknowledge as in the train stop system.

From the foregoing it will be appreciated that applicant has succeededin developing train control and the cab signalling equipment which isvery simple and Will operate in an absolutely reliable manner.

What is claimed is:

1. In a relay operable by magnetic induction, an inductor plane havingthree poles, a second inductor plane also having three poles and a thirdinductor plane having but one pole, an armature associated with one poleof each of the first inductor planes, a second armature associated withanother pole of each of the first tvvo inductor planes and a third yarmature associated With the third poles of the first two inductorplanes and with the pole ofthe third inductor plane.

2. In a relay Which has three armatures operable by inductive action, aplurality of pole pieces, certain of said pole nieces being effectivewhen the relay is placed in one character of inductive field to causethe actuation of all of said armatures in one direction and effectiveWhen placed in an inductive held of an opposite character to restoresaid arma tures and another of said pole pieces being effective When therelay is placed in a magnetic field of a third character to actuate onlyone of said armatures to the exclusion of the others.

3. In a relay operable by magnetic induction, a plurality of armatures,a magnetic flux collecting plate individual to one of said armatures,other magnetic flux collecting plates common to a plurality of saidarmatures, all of said flux collecting plates being selectivelymagnetically influenceable to actuate one or a plurality of saidarmatures.

Il. In a relay, three armatures, and a plurality of magnetic fluxcollecting plates each having pole-pieces for influencing all of saidarmatures.

5. In a relay, three armatures, a plurality of magnetic flux collectingplates each having pole-pieces for influencing all of said armatures,anda third collector plate having influence over one of said armaturesonly.

6. In a relay, a plurality of armatures, a pair of like means arrangedlad]acentsa1d In witness whereof, I hereunto subscribe

